From patchwork Sat Jul 9 10:57:14 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tixy X-Patchwork-Id: 959412 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p69BJK9S008389 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sat, 9 Jul 2011 11:19:41 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QfVXR-0001dp-RQ; Sat, 09 Jul 2011 11:17:35 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QfVQ8-0007jb-Cy; Sat, 09 Jul 2011 11:10:00 +0000 Received: from casper.infradead.org ([2001:770:15f::2]) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QfVEm-0004SS-MF for linux-arm-kernel@canuck.infradead.org; Sat, 09 Jul 2011 10:58:16 +0000 Received: from smarthost01.mail.zen.net.uk ([212.23.3.140]) by casper.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QfVEP-0006Cp-Iz for linux-arm-kernel@lists.infradead.org; Sat, 09 Jul 2011 10:57:54 +0000 Received: from [82.69.122.217] (helo=plug1) by smarthost01.mail.zen.net.uk with esmtpsa (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.63) (envelope-from ) id 1QfVEO-0005aM-E6 for linux-arm-kernel@lists.infradead.org; Sat, 09 Jul 2011 10:57:52 +0000 Received: from [192.168.2.20] (helo=computer2) by plug1 with esmtp (Exim 4.72) (envelope-from ) id 1QfVEM-0003hL-BX for linux-arm-kernel@lists.infradead.org; Sat, 09 Jul 2011 11:57:50 +0100 Received: from tixy by computer2 with local (Exim 4.72) (envelope-from ) id 1QfVEM-0005UO-43 for linux-arm-kernel@lists.infradead.org; Sat, 09 Jul 2011 11:57:50 +0100 From: Tixy To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 27/51] ARM: kprobes: Decode 16-bit Thumb PC- and SP-relative address instructions Date: Sat, 9 Jul 2011 11:57:14 +0100 Message-Id: <1310209058-20980-28-git-send-email-tixy@yxit.co.uk> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1310209058-20980-1-git-send-email-tixy@yxit.co.uk> References: <1310209058-20980-1-git-send-email-tixy@yxit.co.uk> X-Originating-Smarthost01-IP: [82.69.122.217] X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110709_115753_747032_6CBC0F25 X-CRM114-Status: GOOD ( 15.45 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2-r929478 on casper.infradead.org summary: Content analysis details: (-1.9 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.23.3.140 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Sat, 09 Jul 2011 11:19:41 +0000 (UTC) From: Jon Medhurst Signed-off-by: Jon Medhurst --- arch/arm/kernel/kprobes-thumb.c | 33 +++++++++++++++++++++++++++++++++ 1 files changed, 33 insertions(+), 0 deletions(-) diff --git a/arch/arm/kernel/kprobes-thumb.c b/arch/arm/kernel/kprobes-thumb.c index 632a5e8..2b30828 100644 --- a/arch/arm/kernel/kprobes-thumb.c +++ b/arch/arm/kernel/kprobes-thumb.c @@ -74,6 +74,28 @@ t16_simulate_ldrstr_sp_relative(struct kprobe *p, struct pt_regs *regs) base[index] = regs->uregs[rt]; } +static void __kprobes +t16_simulate_reladr(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + unsigned long base = (insn & 0x800) ? regs->ARM_sp + : (thumb_probe_pc(p) & ~3); + long offset = insn & 0xff; + int rt = (insn >> 8) & 0x7; + regs->uregs[rt] = base + offset * 4; +} + +static void __kprobes +t16_simulate_add_sp_imm(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + long imm = insn & 0x7f; + if (insn & 0x80) /* SUB */ + regs->ARM_sp -= imm * 4; + else /* ADD */ + regs->ARM_sp += imm * 4; +} + static unsigned long __kprobes t16_emulate_loregs(struct kprobe *p, struct pt_regs *regs) { @@ -154,6 +176,10 @@ t16_decode_hiregs(kprobe_opcode_t insn, struct arch_specific_insn *asi) static const union decode_item t16_table_1011[] = { /* Miscellaneous 16-bit instructions */ + /* ADD (SP plus immediate) 1011 0000 0xxx xxxx */ + /* SUB (SP minus immediate) 1011 0000 1xxx xxxx */ + DECODE_SIMULATE (0xff00, 0xb000, t16_simulate_add_sp_imm), + /* * If-Then, and hints * 1011 1111 xxxx xxxx @@ -274,6 +300,13 @@ const union decode_item kprobe_decode_thumb16_table[] = { DECODE_SIMULATE (0xf000, 0x9000, t16_simulate_ldrstr_sp_relative), /* + * Generate PC-/SP-relative address + * ADR (literal) 1010 0xxx xxxx xxxx + * ADD (SP plus immediate) 1010 1xxx xxxx xxxx + */ + DECODE_SIMULATE (0xf000, 0xa000, t16_simulate_reladr), + + /* * Miscellaneous 16-bit instructions * 1011 xxxx xxxx xxxx */